Analysis of heart, lung and vascular disorders by means of noninvasive auscultation has long been a very useful tool for medical diagnosis of ailments. By using a stethoscope, a physician would listen to the heart sounds, chest sounds or other body sounds to identify sounds associated with abnormalities. The stethoscope has proven to be a valuable instrument for the transmission of these sounds to the examining physician. However, identifying specific murmurs, like identifying heart sounds, is difficult. Developing the skill to make a proper analysis takes years of study and practice. In addition, it has been recognized that there is a need for amplifying certain frequency areas relative to those which are effectively reproduced by a stethoscope so as to provide physicians with improved sound quality for enhancing diagnosis of abnormalities.
Conventional stethoscope had been invented and used for over 190 years since Year 1816 while electronic stethoscopes was developed not until Year 1922. Modern electronic stethoscopes can improve sound quality and provide visual indication of heart sounds or chest sounds, such as cardiophonography. However, early electronic stethoscopes, which are composed of vacuum tubes or transistors, are typically expensive and bulkier than conventional stethoscopes. Accordingly, electronic stethoscopes can only begin to replace the dominant role of conventional stethoscopes after the rapid development of IC technology at the end of 20th century. Nevertheless, most electronic stethoscopes currently available on the market are analog electronic stethoscopes that are still lacking of the convenient of a conventional stethoscope.
In a prior-art electronic stethoscope disclosed in U.S. Pub. No. 2005/0157888 A1, entitled “Electronic Stethoscope with Piezo-Electrical Film Contact Microphone”, the auscultatory sounds are first being amplified and then the amplified sounds are sent to a filter for eliminating unwanted sounds. Although the aforesaid electronic stethoscope is able to eliminate unwanted sound in an auscultatory process, it is still imperfect that the elimination is realized by a very complex signal processing operation and apparatuses, and a physician using the referring stethoscope to perform an auscultatory process is still bothered by ambient noises, e.g. a bumping sound of a collision happening in the vicinity of the auscultatory being performed.
Therefore, it is in need of a stethoscope capable of effectively eliminating unwanted sounds generating by frictions, translations, or collisions during an auscultatory process for improving auscultation quality by the use of a stethoscope head containing a sensor and a signal processing circuit, such that a physicians can exercise a diagnosis of abnormalities with less effort and time and without being interfered by noises.